diff --git a/doc/opengl-support.dox b/doc/opengl-support.dox
index 395ae2646..2852601f5 100644
--- a/doc/opengl-support.dox
+++ b/doc/opengl-support.dox
@@ -454,6 +454,7 @@ Extension                                   | Status
 @gl_extension{EXT,sRGB_write_control}       | done
 @gl_extension{EXT,texture_compression_s3tc} | done
 @gl_extension{EXT,shader_integer_mix}       | done (shading language only)
+@gl_extension{EXT,polygon_offset_clamp}     | |
 @gl_extension{EXT,texture_compression_s3tc_srgb} | |
 @gl_extension2{KHR,texture_compression_astc_hdr,KHR_texture_compression_astc_hdr} | done
 @gl_extension2{KHR,blend_equation_advanced_coherent,KHR_blend_equation_advanced} | done
diff --git a/src/MagnumExternal/OpenGL/GLES2/extensions.txt b/src/MagnumExternal/OpenGL/GLES2/extensions.txt
index 0284bd590..b1985999d 100644
--- a/src/MagnumExternal/OpenGL/GLES2/extensions.txt
+++ b/src/MagnumExternal/OpenGL/GLES2/extensions.txt
@@ -80,6 +80,7 @@ extension EXT_disjoint_timer_query              optional
 extension EXT_texture_sRGB_decode               optional
 extension EXT_sRGB_write_control                optional
 extension EXT_texture_compression_s3tc          optional
+extension EXT_polygon_offset_clamp              optional
 extension EXT_texture_compression_s3tc_srgb     optional
 extension KHR_texture_compression_astc_hdr      optional
 extension KHR_blend_equation_advanced_coherent  optional
diff --git a/src/MagnumExternal/OpenGL/GLES2/flextGL.cpp b/src/MagnumExternal/OpenGL/GLES2/flextGL.cpp
index 15903a93b..d85b198b0 100644
--- a/src/MagnumExternal/OpenGL/GLES2/flextGL.cpp
+++ b/src/MagnumExternal/OpenGL/GLES2/flextGL.cpp
@@ -101,6 +101,9 @@ FLEXTGL_EXPORT void(APIENTRY *flextglGetQueryObjectuivEXT)(GLuint, GLenum, GLuin
 FLEXTGL_EXPORT void(APIENTRY *flextglGetQueryivEXT)(GLenum, GLenum, GLint *) = nullptr;
 FLEXTGL_EXPORT GLboolean(APIENTRY *flextglIsQueryEXT)(GLuint) = nullptr;
 
+/* GL_EXT_polygon_offset_clamp */
+FLEXTGL_EXPORT void(APIENTRY *flextglPolygonOffsetClampEXT)(GLfloat, GLfloat, GLfloat) = nullptr;
+
 /* GL_EXT_robustness */
 FLEXTGL_EXPORT GLenum(APIENTRY *flextglGetGraphicsResetStatusEXT)(void) = nullptr;
 FLEXTGL_EXPORT void(APIENTRY *flextglGetnUniformfvEXT)(GLuint, GLint, GLsizei, GLfloat *) = nullptr;
diff --git a/src/MagnumExternal/OpenGL/GLES2/flextGL.h b/src/MagnumExternal/OpenGL/GLES2/flextGL.h
index 8cb79f1ba..58a290738 100644
--- a/src/MagnumExternal/OpenGL/GLES2/flextGL.h
+++ b/src/MagnumExternal/OpenGL/GLES2/flextGL.h
@@ -987,6 +987,10 @@ typedef void (APIENTRY *GLDEBUGPROCKHR)(GLenum source,GLenum type,GLuint id,GLen
 #define GL_COMPRESSED_RGBA_S3TC_DXT3_EXT 0x83F2
 #define GL_COMPRESSED_RGBA_S3TC_DXT5_EXT 0x83F3
 
+/* GL_EXT_polygon_offset_clamp */
+
+#define GL_POLYGON_OFFSET_CLAMP_EXT 0x8E1B
+
 /* GL_EXT_texture_compression_s3tc_srgb */
 
 #define GL_COMPRESSED_SRGB_S3TC_DXT1_EXT 0x8C4C
@@ -1348,6 +1352,11 @@ GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglGetQueryivEXT)(GLenum, GLenum, GLint
 GLAPI FLEXTGL_EXPORT GLboolean(APIENTRY *flextglIsQueryEXT)(GLuint);
 #define glIsQueryEXT flextglIsQueryEXT
 
+/* GL_EXT_polygon_offset_clamp */
+
+GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglPolygonOffsetClampEXT)(GLfloat, GLfloat, GLfloat);
+#define glPolygonOffsetClampEXT flextglPolygonOffsetClampEXT
+
 /* GL_EXT_robustness */
 
 GLAPI FLEXTGL_EXPORT GLenum(APIENTRY *flextglGetGraphicsResetStatusEXT)(void);
diff --git a/src/MagnumExternal/OpenGL/GLES2/flextGLPlatform.cpp b/src/MagnumExternal/OpenGL/GLES2/flextGLPlatform.cpp
index ac687633c..bf8e72227 100644
--- a/src/MagnumExternal/OpenGL/GLES2/flextGLPlatform.cpp
+++ b/src/MagnumExternal/OpenGL/GLES2/flextGLPlatform.cpp
@@ -105,6 +105,9 @@ void flextGLInit(Magnum::GL::Context&) {
     flextglGetQueryivEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum, GLint *)>(loader.load("glGetQueryivEXT"));
     flextglIsQueryEXT = reinterpret_cast<GLboolean(APIENTRY*)(GLuint)>(loader.load("glIsQueryEXT"));
 
+    /* GL_EXT_polygon_offset_clamp */
+    flextglPolygonOffsetClampEXT = reinterpret_cast<void(APIENTRY*)(GLfloat, GLfloat, GLfloat)>(loader.load("glPolygonOffsetClampEXT"));
+
     /* GL_EXT_robustness */
     flextglGetGraphicsResetStatusEXT = reinterpret_cast<GLenum(APIENTRY*)(void)>(loader.load("glGetGraphicsResetStatusEXT"));
     flextglGetnUniformfvEXT = reinterpret_cast<void(APIENTRY*)(GLuint, GLint, GLsizei, GLfloat *)>(loader.load("glGetnUniformfvEXT"));
diff --git a/src/MagnumExternal/OpenGL/GLES2/flextGLPlatformIOS.cpp b/src/MagnumExternal/OpenGL/GLES2/flextGLPlatformIOS.cpp
index cbf4819ed..c2efd9d25 100644
--- a/src/MagnumExternal/OpenGL/GLES2/flextGLPlatformIOS.cpp
+++ b/src/MagnumExternal/OpenGL/GLES2/flextGLPlatformIOS.cpp
@@ -67,6 +67,7 @@
 #undef glGetQueryObjectuivEXT
 #undef glGetQueryivEXT
 #undef glIsQueryEXT
+#undef glPolygonOffsetClampEXT
 #undef glGetGraphicsResetStatusEXT
 #undef glGetnUniformfvEXT
 #undef glGetnUniformivEXT
@@ -259,6 +260,11 @@ void flextGLInit(Magnum::GL::Context&) {
     flextglIsQueryEXT = reinterpret_cast<GLboolean(APIENTRY*)(GLuint)>(glIsQueryEXT);
     #endif
 
+    /* GL_EXT_polygon_offset_clamp */
+    #if GL_EXT_polygon_offset_clamp
+    flextglPolygonOffsetClampEXT = reinterpret_cast<void(APIENTRY*)(GLfloat, GLfloat, GLfloat)>(glPolygonOffsetClampEXT);
+    #endif
+
     /* GL_EXT_robustness */
     #if GL_EXT_robustness
     flextglGetGraphicsResetStatusEXT = reinterpret_cast<GLenum(APIENTRY*)(void)>(glGetGraphicsResetStatusEXT);
diff --git a/src/MagnumExternal/OpenGL/GLES2/flextGLPlatformWindowsDesktop.cpp b/src/MagnumExternal/OpenGL/GLES2/flextGLPlatformWindowsDesktop.cpp
index c86977630..e9d9ef3d6 100644
--- a/src/MagnumExternal/OpenGL/GLES2/flextGLPlatformWindowsDesktop.cpp
+++ b/src/MagnumExternal/OpenGL/GLES2/flextGLPlatformWindowsDesktop.cpp
@@ -204,6 +204,9 @@ void flextGLInit(Magnum::GL::Context&) {
     flextglGetQueryivEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum, GLint *)>(loader.load("glGetQueryivEXT"));
     flextglIsQueryEXT = reinterpret_cast<GLboolean(APIENTRY*)(GLuint)>(loader.load("glIsQueryEXT"));
 
+    /* GL_EXT_polygon_offset_clamp */
+    flextglPolygonOffsetClampEXT = reinterpret_cast<void(APIENTRY*)(GLfloat, GLfloat, GLfloat)>(loader.load("glPolygonOffsetClampEXT"));
+
     /* GL_EXT_robustness */
     flextglGetGraphicsResetStatusEXT = reinterpret_cast<GLenum(APIENTRY*)(void)>(loader.load("glGetGraphicsResetStatusEXT"));
     flextglGetnUniformfvEXT = reinterpret_cast<void(APIENTRY*)(GLuint, GLint, GLsizei, GLfloat *)>(loader.load("glGetnUniformfvEXT"));
diff --git a/src/MagnumExternal/OpenGL/GLES2/flextGLWindowsDesktop.cpp b/src/MagnumExternal/OpenGL/GLES2/flextGLWindowsDesktop.cpp
index 3a8b4f687..1c1b62874 100644
--- a/src/MagnumExternal/OpenGL/GLES2/flextGLWindowsDesktop.cpp
+++ b/src/MagnumExternal/OpenGL/GLES2/flextGLWindowsDesktop.cpp
@@ -200,6 +200,9 @@ FLEXTGL_EXPORT void(APIENTRY *flextglGetQueryObjectuivEXT)(GLuint, GLenum, GLuin
 FLEXTGL_EXPORT void(APIENTRY *flextglGetQueryivEXT)(GLenum, GLenum, GLint *) = nullptr;
 FLEXTGL_EXPORT GLboolean(APIENTRY *flextglIsQueryEXT)(GLuint) = nullptr;
 
+/* GL_EXT_polygon_offset_clamp */
+FLEXTGL_EXPORT void(APIENTRY *flextglPolygonOffsetClampEXT)(GLfloat, GLfloat, GLfloat) = nullptr;
+
 /* GL_EXT_robustness */
 FLEXTGL_EXPORT GLenum(APIENTRY *flextglGetGraphicsResetStatusEXT)(void) = nullptr;
 FLEXTGL_EXPORT void(APIENTRY *flextglGetnUniformfvEXT)(GLuint, GLint, GLsizei, GLfloat *) = nullptr;
diff --git a/src/MagnumExternal/OpenGL/GLES2/flextGLWindowsDesktop.h b/src/MagnumExternal/OpenGL/GLES2/flextGLWindowsDesktop.h
index 3e1495917..b0c4d4118 100644
--- a/src/MagnumExternal/OpenGL/GLES2/flextGLWindowsDesktop.h
+++ b/src/MagnumExternal/OpenGL/GLES2/flextGLWindowsDesktop.h
@@ -982,6 +982,10 @@ typedef void (APIENTRY *GLDEBUGPROCKHR)(GLenum source,GLenum type,GLuint id,GLen
 #define GL_COMPRESSED_RGBA_S3TC_DXT3_EXT 0x83F2
 #define GL_COMPRESSED_RGBA_S3TC_DXT5_EXT 0x83F3
 
+/* GL_EXT_polygon_offset_clamp */
+
+#define GL_POLYGON_OFFSET_CLAMP_EXT 0x8E1B
+
 /* GL_EXT_texture_compression_s3tc_srgb */
 
 #define GL_COMPRESSED_SRGB_S3TC_DXT1_EXT 0x8C4C
@@ -1440,6 +1444,11 @@ GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglGetQueryivEXT)(GLenum, GLenum, GLint
 GLAPI FLEXTGL_EXPORT GLboolean(APIENTRY *flextglIsQueryEXT)(GLuint);
 #define glIsQueryEXT flextglIsQueryEXT
 
+/* GL_EXT_polygon_offset_clamp */
+
+GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglPolygonOffsetClampEXT)(GLfloat, GLfloat, GLfloat);
+#define glPolygonOffsetClampEXT flextglPolygonOffsetClampEXT
+
 /* GL_EXT_robustness */
 
 GLAPI FLEXTGL_EXPORT GLenum(APIENTRY *flextglGetGraphicsResetStatusEXT)(void);
diff --git a/src/MagnumExternal/OpenGL/GLES3/extensions.txt b/src/MagnumExternal/OpenGL/GLES3/extensions.txt
index 012a305e0..ccc96d3bc 100644
--- a/src/MagnumExternal/OpenGL/GLES3/extensions.txt
+++ b/src/MagnumExternal/OpenGL/GLES3/extensions.txt
@@ -45,8 +45,9 @@ extension EXT_disjoint_timer_query                  optional
 extension EXT_texture_sRGB_decode                   optional
 extension EXT_sRGB_write_control                    optional
 extension EXT_texture_compression_s3tc              optional
-extension EXT_texture_compression_s3tc_srgb         optional
 extension EXT_shader_integer_mix                    optional
+extension EXT_polygon_offset_clamp                  optional
+extension EXT_texture_compression_s3tc_srgb         optional
 extension KHR_texture_compression_astc_hdr          optional
 extension KHR_blend_equation_advanced_coherent      optional
 extension KHR_context_flush_control                 optional
diff --git a/src/MagnumExternal/OpenGL/GLES3/flextGL.cpp b/src/MagnumExternal/OpenGL/GLES3/flextGL.cpp
index 87ae1ad96..fd7b0955d 100644
--- a/src/MagnumExternal/OpenGL/GLES3/flextGL.cpp
+++ b/src/MagnumExternal/OpenGL/GLES3/flextGL.cpp
@@ -191,6 +191,9 @@ FLEXTGL_EXPORT void(APIENTRY *flextglMultiDrawElementsEXT)(GLenum, const GLsizei
 FLEXTGL_EXPORT void(APIENTRY *flextglFramebufferTexture2DMultisampleEXT)(GLenum, GLenum, GLenum, GLuint, GLint, GLsizei) = nullptr;
 FLEXTGL_EXPORT void(APIENTRY *flextglRenderbufferStorageMultisampleEXT)(GLenum, GLsizei, GLenum, GLsizei, GLsizei) = nullptr;
 
+/* GL_EXT_polygon_offset_clamp */
+FLEXTGL_EXPORT void(APIENTRY *flextglPolygonOffsetClampEXT)(GLfloat, GLfloat, GLfloat) = nullptr;
+
 /* GL_EXT_primitive_bounding_box */
 FLEXTGL_EXPORT void(APIENTRY *flextglPrimitiveBoundingBoxEXT)(GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat) = nullptr;
 
diff --git a/src/MagnumExternal/OpenGL/GLES3/flextGL.h b/src/MagnumExternal/OpenGL/GLES3/flextGL.h
index 4a9a5fff1..ece5f1a6c 100644
--- a/src/MagnumExternal/OpenGL/GLES3/flextGL.h
+++ b/src/MagnumExternal/OpenGL/GLES3/flextGL.h
@@ -1526,6 +1526,10 @@ typedef void (APIENTRY *GLDEBUGPROCKHR)(GLenum source,GLenum type,GLuint id,GLen
 #define GL_COMPRESSED_RGBA_S3TC_DXT3_EXT 0x83F2
 #define GL_COMPRESSED_RGBA_S3TC_DXT5_EXT 0x83F3
 
+/* GL_EXT_polygon_offset_clamp */
+
+#define GL_POLYGON_OFFSET_CLAMP_EXT 0x8E1B
+
 /* GL_EXT_texture_compression_s3tc_srgb */
 
 #define GL_COMPRESSED_SRGB_S3TC_DXT1_EXT 0x8C4C
@@ -2179,6 +2183,11 @@ GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglFramebufferTexture2DMultisampleEXT)(G
 GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglRenderbufferStorageMultisampleEXT)(GLenum, GLsizei, GLenum, GLsizei, GLsizei);
 #define glRenderbufferStorageMultisampleEXT flextglRenderbufferStorageMultisampleEXT
 
+/* GL_EXT_polygon_offset_clamp */
+
+GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglPolygonOffsetClampEXT)(GLfloat, GLfloat, GLfloat);
+#define glPolygonOffsetClampEXT flextglPolygonOffsetClampEXT
+
 /* GL_EXT_primitive_bounding_box */
 
 GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglPrimitiveBoundingBoxEXT)(GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat);
diff --git a/src/MagnumExternal/OpenGL/GLES3/flextGLPlatform.cpp b/src/MagnumExternal/OpenGL/GLES3/flextGLPlatform.cpp
index 777e467dc..c052713a5 100644
--- a/src/MagnumExternal/OpenGL/GLES3/flextGLPlatform.cpp
+++ b/src/MagnumExternal/OpenGL/GLES3/flextGLPlatform.cpp
@@ -195,6 +195,9 @@ void flextGLInit(Magnum::GL::Context&) {
     flextglFramebufferTexture2DMultisampleEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum, GLenum, GLuint, GLint, GLsizei)>(loader.load("glFramebufferTexture2DMultisampleEXT"));
     flextglRenderbufferStorageMultisampleEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLsizei, GLenum, GLsizei, GLsizei)>(loader.load("glRenderbufferStorageMultisampleEXT"));
 
+    /* GL_EXT_polygon_offset_clamp */
+    flextglPolygonOffsetClampEXT = reinterpret_cast<void(APIENTRY*)(GLfloat, GLfloat, GLfloat)>(loader.load("glPolygonOffsetClampEXT"));
+
     /* GL_EXT_primitive_bounding_box */
     flextglPrimitiveBoundingBoxEXT = reinterpret_cast<void(APIENTRY*)(GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat)>(loader.load("glPrimitiveBoundingBoxEXT"));
 
diff --git a/src/MagnumExternal/OpenGL/GLES3/flextGLPlatformIOS.cpp b/src/MagnumExternal/OpenGL/GLES3/flextGLPlatformIOS.cpp
index ae251dafa..7d3ffd8ca 100644
--- a/src/MagnumExternal/OpenGL/GLES3/flextGLPlatformIOS.cpp
+++ b/src/MagnumExternal/OpenGL/GLES3/flextGLPlatformIOS.cpp
@@ -55,6 +55,7 @@
 #undef glMultiDrawElementsEXT
 #undef glFramebufferTexture2DMultisampleEXT
 #undef glRenderbufferStorageMultisampleEXT
+#undef glPolygonOffsetClampEXT
 #undef glPrimitiveBoundingBoxEXT
 #undef glGetGraphicsResetStatusEXT
 #undef glGetnUniformfvEXT
@@ -205,6 +206,11 @@ void flextGLInit(Magnum::GL::Context&) {
     flextglRenderbufferStorageMultisampleEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLsizei, GLenum, GLsizei, GLsizei)>(glRenderbufferStorageMultisampleEXT);
     #endif
 
+    /* GL_EXT_polygon_offset_clamp */
+    #if GL_EXT_polygon_offset_clamp
+    flextglPolygonOffsetClampEXT = reinterpret_cast<void(APIENTRY*)(GLfloat, GLfloat, GLfloat)>(glPolygonOffsetClampEXT);
+    #endif
+
     /* GL_EXT_primitive_bounding_box */
     #if GL_EXT_primitive_bounding_box
     flextglPrimitiveBoundingBoxEXT = reinterpret_cast<void(APIENTRY*)(GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat)>(glPrimitiveBoundingBoxEXT);
diff --git a/src/MagnumExternal/OpenGL/GLES3/flextGLPlatformWindowsDesktop.cpp b/src/MagnumExternal/OpenGL/GLES3/flextGLPlatformWindowsDesktop.cpp
index 4fc15b9e1..2378be507 100644
--- a/src/MagnumExternal/OpenGL/GLES3/flextGLPlatformWindowsDesktop.cpp
+++ b/src/MagnumExternal/OpenGL/GLES3/flextGLPlatformWindowsDesktop.cpp
@@ -397,6 +397,9 @@ void flextGLInit(Magnum::GL::Context&) {
     flextglFramebufferTexture2DMultisampleEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLenum, GLenum, GLuint, GLint, GLsizei)>(loader.load("glFramebufferTexture2DMultisampleEXT"));
     flextglRenderbufferStorageMultisampleEXT = reinterpret_cast<void(APIENTRY*)(GLenum, GLsizei, GLenum, GLsizei, GLsizei)>(loader.load("glRenderbufferStorageMultisampleEXT"));
 
+    /* GL_EXT_polygon_offset_clamp */
+    flextglPolygonOffsetClampEXT = reinterpret_cast<void(APIENTRY*)(GLfloat, GLfloat, GLfloat)>(loader.load("glPolygonOffsetClampEXT"));
+
     /* GL_EXT_primitive_bounding_box */
     flextglPrimitiveBoundingBoxEXT = reinterpret_cast<void(APIENTRY*)(GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat)>(loader.load("glPrimitiveBoundingBoxEXT"));
 
diff --git a/src/MagnumExternal/OpenGL/GLES3/flextGLWindowsDesktop.cpp b/src/MagnumExternal/OpenGL/GLES3/flextGLWindowsDesktop.cpp
index 014d8f25b..225140591 100644
--- a/src/MagnumExternal/OpenGL/GLES3/flextGLWindowsDesktop.cpp
+++ b/src/MagnumExternal/OpenGL/GLES3/flextGLWindowsDesktop.cpp
@@ -393,6 +393,9 @@ FLEXTGL_EXPORT void(APIENTRY *flextglMultiDrawElementsEXT)(GLenum, const GLsizei
 FLEXTGL_EXPORT void(APIENTRY *flextglFramebufferTexture2DMultisampleEXT)(GLenum, GLenum, GLenum, GLuint, GLint, GLsizei) = nullptr;
 FLEXTGL_EXPORT void(APIENTRY *flextglRenderbufferStorageMultisampleEXT)(GLenum, GLsizei, GLenum, GLsizei, GLsizei) = nullptr;
 
+/* GL_EXT_polygon_offset_clamp */
+FLEXTGL_EXPORT void(APIENTRY *flextglPolygonOffsetClampEXT)(GLfloat, GLfloat, GLfloat) = nullptr;
+
 /* GL_EXT_primitive_bounding_box */
 FLEXTGL_EXPORT void(APIENTRY *flextglPrimitiveBoundingBoxEXT)(GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat) = nullptr;
 
diff --git a/src/MagnumExternal/OpenGL/GLES3/flextGLWindowsDesktop.h b/src/MagnumExternal/OpenGL/GLES3/flextGLWindowsDesktop.h
index 01f64ec99..6bfaa0f0f 100644
--- a/src/MagnumExternal/OpenGL/GLES3/flextGLWindowsDesktop.h
+++ b/src/MagnumExternal/OpenGL/GLES3/flextGLWindowsDesktop.h
@@ -1518,6 +1518,10 @@ typedef void (APIENTRY *GLDEBUGPROCKHR)(GLenum source,GLenum type,GLuint id,GLen
 #define GL_COMPRESSED_RGBA_S3TC_DXT3_EXT 0x83F2
 #define GL_COMPRESSED_RGBA_S3TC_DXT5_EXT 0x83F3
 
+/* GL_EXT_polygon_offset_clamp */
+
+#define GL_POLYGON_OFFSET_CLAMP_EXT 0x8E1B
+
 /* GL_EXT_texture_compression_s3tc_srgb */
 
 #define GL_COMPRESSED_SRGB_S3TC_DXT1_EXT 0x8C4C
@@ -2369,6 +2373,11 @@ GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglFramebufferTexture2DMultisampleEXT)(G
 GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglRenderbufferStorageMultisampleEXT)(GLenum, GLsizei, GLenum, GLsizei, GLsizei);
 #define glRenderbufferStorageMultisampleEXT flextglRenderbufferStorageMultisampleEXT
 
+/* GL_EXT_polygon_offset_clamp */
+
+GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglPolygonOffsetClampEXT)(GLfloat, GLfloat, GLfloat);
+#define glPolygonOffsetClampEXT flextglPolygonOffsetClampEXT
+
 /* GL_EXT_primitive_bounding_box */
 
 GLAPI FLEXTGL_EXPORT void(APIENTRY *flextglPrimitiveBoundingBoxEXT)(GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat, GLfloat);